1. Field of the Invention
The present invention relates to a video processing apparatus and a video processing method for controlling a video image playback speed.
2. Description of the Related Art
Recently, video cameras capable of shooting an image at various frame rates from a low frame rate of about 30 fps (frame per second) to more than 1000 fps, have been used. With this video camera, it is possible to dynamically switch the shooting frame rate during shooting. On the other hand, the frame rate when images are played back on a video player is generally 60 fps or 120 fps.
By using a difference between a shooting frame rate on a video camera and a playback frame rate on a video player, image display with special image effects can be obtained. For example, when a shooting frame rate is higher than a playback frame rate, a displayed image becomes a slow play image with a smooth motion. On the other hand, when the shooting frame rate is lower than the playback frame rate, a displayed image becomes a fast play image with a fast motion.
On the other hand, when an image including audio data is played back in a slow speed, the playback speed of sound becomes slow, so that a compass of a playback sound becomes lower than a real range, and it sometimes becomes difficult to catch the sound or voice (speech). On the other hand, when the image is played back in a fast speed, the compass of the playback sound becomes higher than a real range and it sometimes becomes difficult to catch the sound or voice.
Japanese Patent Application Laid-Open No. 2002-314945 discusses a speech rate conversion system that detects sound sections and soundless sections of the image, and partially deletes audio data of the soundless sections based on a playback speed specified by a user to thereby generate audio data to be output.
However, conventionally, audio data has been corrected uniformly based on a playback speed set by the user. Therefore, a sound that is easy to catch may not be outputted. Moreover, it has been difficult to adequately correct audio data if multi-frame rate video contents with different shooting (recording) frame rates are included in a single video content.